Giant potato rösti

Method

1. Put a large glug of olive oil and a large knob of butter in a frying pan over a low-medium heat. When hot, add the onions and garlic and cook for 15-20 minutes until soft, sweet and golden. Add the thyme for the last few minutes. Cool slightly.
2. Meanwhile heat the oven to 200°C/180°C fan/gas 6. Grate the potatoes on a box grater and wrap in a clean tea towel. Press it hard against the side of the sink for a few minutes to squeeze out as much liquid as you can.
3. Grease a 23cm short-sided cake tin (see tip) with a removable base (not a springform tin, from which the rösti would be difficult to remove). Put the squeezed grated potato in a large mixing bowl with the cooled onion mixture, together with the salt, eggs, chives and some freshly ground black pepper. Mix well with your hands and put in the cake tin (don’t pack it down too tightly). Cook the rösti for 1 hour, then remove, dot the 30g butter over the surface and put back in the oven for another 15 minutes or until golden brown on the top. Remove from the tin and serve straightaway or just warm.